The most common serum preparation considerations include:
• Failure to separate serum from red cells within 15 to 30 minutes of venipuncture.
• Failure to allow clot specimens to clot before centrifugation.
• Hemolysis: red blood cells broken down and components spilled into serum. Causes and prevention are discussed under the section on hemolysis.
• Lipemia: cloudy or milky serum sometimes due to the patient’s diet.